问:用乘法运算定律计算下面各题.752×1.25+4.45×12.5+0.035×

问题描述:

问:用乘法运算定律计算下面各题.752×1.25+4.45×12.5+0.035×
问:用乘法运算定律计算下面各题.
752×1.25+4.45×12.5+0.035×125
0.42×160+36×1.6-31×3.2
1.625+2.625+3.625+...+79.625+80.625

752×1.25+4.45×12.5+0.035×125=752*1.25+44.5*1.25+3.5*1.25=(752+44.5+3.5)*1.25=800*1.25=10000.42×160+36×1.6-31×3.2=42*1.6+36*1.6-63*1.6=(42+36-63)*1.6=15*1.6=241.625+2.625+3.625+...+79.625+80.625...